In 1568, after being deposed from the Scottish throne, Mary Queen of Scots fled to England seeking the aid of her cousin Elizabeth I. Yet, the welcome she received there was far from warm. As a Catholic queen with a strong claim to Elizabeth’s throne, Mary’s very presence in the country presented a threat to English religious and national stability. In acknowledgement of this, not only was Mary detained in captivity, but Elizabeth’s Protestant supporters—even the Elizabethan government itself—engaged in a concentrated campaign of textual defamation against her. Aligning Mary with numerous “evil” women of classical and biblical antiquity, she was condemned as a tyrant, a murderess, a sexually immoral woman who led men astray. These negative textual portrayals of Mary contributed to a nationalist project of defining England and Elizabeth against what Mary represented. By highlighting her Catholicism, her foreignness, her apparently deviant femininity, these texts portrayed Mary as an anti-English archetype against which their own queen could be contrasted. Nation and gender were thus weaponised by one female monarch against another in ways that—because of the peculiarity of the political situation—could not be reproduced elsewhere, offering a unique insight into how England (and Scotland) filtered their self-consciousness about national identities through reference to a rich arsenal of metaphors pertaining to queens.